This is really terrible - CO should take the site down
I just went to CO and I was logged in as someone else and I had some couple's upcoming Aug. trip to Chicago. I could change their seats cancel their flights.
Fortunately, you'd need a password in order to really wreak havoc with some one's credit card etc.
CO should really put the old site back up. In this litigious world, they are risking being sued if someone horses around with someone else's reservation.